Invertebrate Zoology, 2014, 11(2): 293–314 © INVERTEBRATE ZOOLOGY, 2014 Tube morphology, ultrastructures and mineralogy in recent Spirorbinae (Annelida: Polychaeta: Serpulidae). I. General introduction. Tribe Paralaeospirini A.P. Ippolitov1, A.V. Rzhavsky2 1 Geological Institute of Russian Academy of Sciences (GIN RAS), 7 Pyzhevskiy per., Moscow, Russia, 119017, e-mail: [email protected] 2 A.N. Severtsov Institute of Ecology and Evolution of Russian Academy of Sciences (IPEE RAS), 33 Leninskiy prosp., Moscow, Russia, 119071, e-mail: [email protected] ABSTRACT: This report is the first part of a series of papers that provide an overview of tube morphology, mineralogy, and ultrastructures within the subfamily Spirorbinae, includ- ing the discussion of taxonomic and phylogenetic significance of the tube features. This paper reviews published data on the subject and provides descriptions of ultrastructure and mineralogy for the tribe Paralaeospirini Knight-Jones, 1978. The species of the tribe have uniformly simple calcitic unilayered tubes of the same irregularly oriented prismatic (IOP) ultrastructural type, which is regarded as plesiomorphic among serpulids. How to cite this article: Ippolitov A.P., Rzhavsky A.V. 2014. Tube morphology, ultrastruc- tures and mineralogy in recent Spirorbinae (Annelida: Polychaeta: Serpulidae). I. General introduction. Tribe Paralaeospirini // Invert. Zool. Vol. 11. No. 2. KEY WORDS: Tube ultrastructures, tube morphology, tube mineralogy, scanning electron microscopy, X-ray diffraction analysis, Spirorbinae, Paralaeospirini. Морфология, ультраструктуры и минералогия трубок современных Spirorbinae (Annelida: Polychaeta: Serpulidae). I. Общее введение. Материал и методы. Триба Paralaeospirini А.П. Ипполитов1, А.В. Ржавский2 1 Геологический институт РАН, Пыжевский пер. 7, Москва, Россия, 119017, e-mail: [email protected] 2 Институт проблем экологии и эволюции им. А.Н. Северцова РАН, Ленинский пр. 33, Москва, Россия, 119071, e-mail: [email protected] РЕЗЮМЕ: В настоящей серии статей приводится обзор морфологического, ультра- структурного и минералогического разнообразия трубок подсемейства Spirorbinae, а также обсуждается возможное таксономическое и филогенетическое значения признаков трубок. В первой части серии мы приводим обзор опубликованных данных, а также даем описания морфологии трубок, их ультраструктур и минерало- гии для трибы Paralaeospirini Knight-Jones, 1978. Установлено, что виды, представ- ляющие трибу, имеют однослойные кальцитовые трубки из хаотически ориентиро- ванных призматических кристаллов. Данный тип строения трубок интерпретируется как архаичный для серпулид. 294 A.P. Ippolitov, A.V. Rzhavsky Как цитировать эту статью: Ippolitov A.P., Rzhavsky A.V. 2014. Tube morphology, ultrastructures and mineralogy in recent Spirorbinae (Annelida: Polychaeta: Serpulidae). I. General introduction. Tribe Paralaeospirini // Invert. Zool. Vol. 11. No. 2. КЛЮЧЕВЫЕ СЛОВА: Ультраструктура трубок, морфология трубок, минералогия трубок, сканирующая электронная микроскопия, рентгенодифракционный анализ, Spirorbinae, Paralaeospirini. Introduction 1981; Jäger, 1983, 1993) that spirorbins are an ancient group dating back to the Ordovician Subfamily Spirorbinae of the family Serpul- period (~445–485 Ma1), true spirorbins seem to idae Rafinesque, 1815 is a widely distributed appear from the Latest Jurassic or Earliest Cre- group of small marine polychaetes that inhabit taceous (~145 Ma: see Taylor, Vinn, 2006). calcareous tubes tightly coiled into spirals and Non-spirorbin nature of more ancient Paleozoic attached to a variety of substrata. Recent spirorb- to Early Mesozoic tubes, which look undistin- ins have world-wide distribution ranging from guishable from spirorbins by external morphol- littoral to abyssal depths, but are most common- ogy, was recognized by morphology of their ly found in the sublittoral zone. internal septae (Burchette, Riding, 1977), study Family Serpulidae was traditionally subdi- of tube microstructures (Burchette, Riding, 1977; vided into subfamilies Spirorbinae Chamberlin, Weedon, 1990, 1991) and comparison with 1919, Serpulinae Rafinesque, 1815, and Filog- those of Recent forms (Weedon, 1994; Taylor, raninae Rioja (1923) (e.g., Rioja, 1923; Fauvel, Vinn, 2006). These ancient fossils are now 1927). Pillai (1970) elevated Spirorbinae to the placed not only outside Spirorbinae, but also family status, which was accepted both in Re- outside the phylum Annelida (see Vinn, Taylor, cent and fossil taxonomy (e.g., Knight-Jones P., 2007). Fordy M., 1979; Lommerzheim, 1981; Jäger, During the Cretaceous period (145–66 Ma), 1993, 2005; Rzhavsky, 1994). Later numerous coiled serpulids attributed to spirorbins were authors (e.g., ten Hove, 1984; Smith, 1991, represented mostly by the large-sized and pecu- Kupriyanova, 2003; Kupriyanova et al., 2006; liar genus Neomicrorbis Rovereto, 1903. The Lehrke et al., 2007), based on the results of most ancient finds of this genus are described phylogenetic analyses of morphological and from the Late Barremian (~128 Ma; Jäger, 2011), molecular data, concluded that spirorbins con- but finds of somewhat similar tubes are more stitute a monophyletic group nested inside the ancient (see Jäger, 1983, 1993, 2011). Neomi- Serpulidae. Therefore, the rank of the spiror- crorbis tubes, unlike most spirorbins, are coiled bids was lowered to the subfamily and all former in any direction and often have characteristic subfamilies established within Spirorbidae (see sculpture of numerous rows of tiny tubercules. Knight-Jones P., Fordy, 1979) became tribes Information on the body morphology available (Rzhavsky et al., 2013). The current state of from the only known Recent species Neomi- classification of Spirorbinae that includes 6 crorbis azoricus Zibrowius, 1972 (Zibrowius, tribes, 24 genera, and 131 (135?) species is 1972; Hove, Kupriyanova, 2006) does not al- summarized in Table 1. low to make a certain conclusion about its phylogenetic position inside Serpulidae. Spirorbin fossil record. Spirorbins calcare- Unquestionable spirorbin species that ap- ous tubes have a good potential to fossilize, peared in the middle of the Early Cretaceous providing a basis for substantial fossil record for these polychaetes. Contrary to the long-held 1 Absolute ages are provided according to official site of the International Commission of Stratigraphy view (e.g., Goldfuss, 1831; Zittel, 1880; How- (www.stratigraphy.org/GSSP/index.html), accessed 01- ell, 1962; Pillai, 1970; Lommerzheim, 1979, 03-2013. Tube morphology, ultrastructures and mineralogy in recent Spirorbinae. I. 295 Table 1. Compiled classification of Recent spirorbins, including tribes, genera and number of valid spe- cies. Some species of uncertain generic affinity are not considered in the table. Таблица 1. Классификация современных спирорбин (трибы, рода и число валидных видов). Некоторые виды неясной родовой принадлежности не учтены. Number of Tribe Genus species Paralaeospirini Knight-Jones, 1978 Paralaeospira Caullery et Mesnil, 1897 10 Anomalorbis Vine, 1972 1 Incertae sedis (Paralaeospirini?) Crozetospira Rzhavsky, 1997 1 Spirorbini Chamberlin, 1919 Spirorbis Daudin, 1800 15 Circeis Saint-Joseph, 1894 6 Circeini Knight-Jones, 1978 Paradexiospira Caullery et Mesnil, 1897 3(4?) Eulaeospira Pillai, 1970 2 Helicosiphon Gravier, 1907 1 Knightjonesia Pillai, 2009 1 Romanchellini Knight-Jones, 1978 Metalaeospira Pillai, 1970 4 Protolaeospira Pixell, 1912 12 Romanchella Caullery et Mesnil, 1897 8 Janua Saint-Joseph, 1894 1 Leodora Saint-Joseph, 1894 1 Januini Knight-Jones, 1978 Neodexiospira Pillai, 1970 10(11?) Pillaiospira Knight-Jones, 1973 3 Amplicaria Knight-Jones, 1984 1 Bushiella Knight-Jones, 1973 13(14?) Nidificaria Knight-Jones, 1984 8 Pileolariini Knight-Jones, 1978 Pileolaria Claparède, 1868 21(22?) Protoleodora Pillai, 1970 4 Simplaria Knight-Jones, 1984 3 Vinearia Knight-Jones, 1984 3 Incertae sedis Neomicrorbis Rovereto, 1903 1 (Late Barremian; ~126 Ma; Jäger, 2011) are phology is less uniform and better studied to represented by tubes, morphologically compa- allow classification of fossil species within Re- rable with those of extant species of genera cent genera (see Jäger, 1993, 2005), while for Pileolaria and Neodexiospira. From the latest spirorbins determination of generic affinity based Cretaceous (Late Maastrichtian; ~66 Ma) spir- on empty tubes remains problematic. As a re- orbins became a very common element of en- sult, despite existing fossil record, zoologists crusting communities (e.g., Jäger, 1983, 1993). still have no reliable paleontological data for Younger Paleogene (Paleocene, 62–59 Ma; Lom- understanding evolutionary history of the group, merzheim, 1981) and especially Neogene (like while paleontologists are restricted in their geo- Badenian, 16–13 Ma; Radwańska, 1994, etc.) logical, paleoecological, and biogeographical sediments already contain highly diversified interpretations because no direct comparison of spirorbin communities similar to Recent ones. fossils with Recent taxa is possible. If determi- Classification of Recent spirorbins is cur- nations of fossil spirorbin tubes from Late Bar- rently built around the methods of embryos remian (~126 Ma) are correct, this means that incubation, as well as body and chaetal charac- two of the Recent tribes characterized by com- ters, while tubes are mostly neglected. This plex incubation methods (Pileolariini and Janu- approach walls off paleontologists who work ini) have already established in the middle Early predominantly